The existence of different forms of out-of-pocket payments (OOPs) for pharmaceuticals across the globe provokes the question whether they can achieve more negative or positive consequences. A systematic literature review was conducted to assess the association between drug cost sharing and health care services utilization, health care costs as well as health outcomes. Studies published in The Cochrane Library, PubMed, Embase were searched with such keywords as: drug, pharmaceutical, cost sharing, out of pocket, co-payments paired with the following: impact, health outcomes, health care costs and utilization. The final review included 18 articles. A total of 11 publications reported the association between drug cost sharing and health care utilization patterns, of which nine found a statistically significant direct relationship. In all 10 publications concerned the association between drug copayments and health care costs. Majority were limited to the impact on the drug budget. Seven studies looked into the link between drug cost sharing and health outcomes, of which five reported statistically significant inverse relationship. There is some evidence for the association between drug copayments, health outcomes and health care services consumption. The optimal system of OOPs’ payments for pharmaceuticals needs to prevent drugs’ overconsumption and mitigate the risks of excessive cost sharing’s burden.